Citizenship expedite process?/

[GennyM]

I married my husband in December 2015, he was a permanent resident
in November 2019 he became a citizen.
I applied for my greencard (10 years without conditions) and got it in February 2020.

when can I apply for citizenship?

[newacct]

So you never got a 2-year green card, right? As long as you remain married to your husband, you can apply for naturalization either 1) 90 days before you have been a permanent resident for 3 years, or 2) 3 years after your husband became a citizen, whichever of those is later. (Both of those dates would be in November 2022, so I can't tell which of them is later.)